[AGC] Quake rendering progress: WAIT_REG_MEM, draw fixes, VideoOut, and HLE improvements (#68)

* [agc] WAIT_REG_MEM suspend/resume, draw packet fixes, new HLE exports, debug cleanup

Rebased onto upstream 79a7437 (par274/sharpemu, rewritten history).

- GpuWaitRegistry: DCBs suspended on unsatisfied WAIT_REG_MEM are re-polled
  against guest memory on every submit; fixed 64-bit and standard packet parse
  offsets, apply the mask, treat PM4 compare function 0 as "always".
- TryReadSubmittedDrawCount: accept the 5-dword ItDrawIndex2 form emitted by
  DcbDrawIndex (count at +4); menu draws were silently discarded before.
- sceAgcDriverSubmitMultiDcbs: reversed ABI (rdi=address array, rsi=dword
  sizes, rdx=count).
- VideoOut: vblank events, sceVideoOutGetFlipStatus, buffers registered via
  sceVideoOutRegisterBuffers are valid flip targets.
- New HLE: libc stdio (fopen/fread/fseek/ftell/fclose/fgets), Dinkumware
  _Getpctype ctype table, NpTrophy2 stubs, AMPR PAK sequential-read tracker,
  MsgDialog lifecycle, NGS2 alt NIDs + dummy vtable for handle objects,
  guarded memset intrinsic, abort()/strcasecmp null-arg recovery.
- Removed investigation-only code (INT3 breakpoints, qfont/mcpp dumps,
  error-candidate printf traces, unconditional debug logs).

First rendered frame: Quake (PPSA01880) presents a 1920x1080 guest frame.

* Implemented a guarded native intrinsic (rep movsb) in DirectExecutionBackend to bypass HLE dispatch overhead, while preserving memory safety checks.

src/SharpEmu.Libs/Ngs2/Ngs2Exports.cs

@@ -13,7 +13,7 @@ public static class Ngs2Exports
     private const int OrbisNgs2ErrorInvalidSystemHandle = unchecked((int)0x804A0230);
     private const int OrbisNgs2ErrorInvalidRackHandle = unchecked((int)0x804A0261);
     private const int OrbisNgs2ErrorInvalidVoiceHandle = unchecked((int)0x804A0300);
-    private const ulong HandleStorageSize = 0x20;
+    private const ulong HandleStorageSize = 0x1000;
     private const int RenderBufferInfoSize = 0x18;
     private const ulong MaximumRenderBufferSize = 16 * 1024 * 1024;
 
@@ -197,12 +197,19 @@ public static class Ngs2Exports
         lock (StateGate)
         {
             return ctx.SetReturn(
-                Voices.ContainsKey(ctx[CpuRegister.Rdi]) 
-                    ? 0 
+                Voices.ContainsKey(ctx[CpuRegister.Rdi])
+                    ? 0
                     : OrbisNgs2ErrorInvalidVoiceHandle);
         }
     }
 
+    [SysAbiExport(
+        Nid = "-4GCfYdNF1s",
+        ExportName = "sceNgs2VoiceControl",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceNgs2")]
+    public static int Ngs2VoiceControlAlt(CpuContext ctx) => Ngs2VoiceControl(ctx);
+
     [SysAbiExport(
         Nid = "AbYvTOZ8Pts",
         ExportName = "sceNgs2VoiceRunCommands",
@@ -210,6 +217,27 @@ public static class Ngs2Exports
         LibraryName = "libSceNgs2")]
     public static int Ngs2VoiceRunCommands(CpuContext ctx) => Ngs2VoiceControl(ctx);
 
+    [SysAbiExport(
+        Nid = "-TOuuAQ-buE",
+        ExportName = "sceNgs2VoiceRunCommands",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceNgs2")]
+    public static int Ngs2VoiceRunCommandsAlt(CpuContext ctx) => Ngs2VoiceControl(ctx);
+
+    [SysAbiExport(
+        Nid = "x8qnXqh-tiM",
+        ExportName = "sceNgs2VoiceGetState",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceNgs2")]
+    public static int Ngs2VoiceGetState(CpuContext ctx) => ctx.SetReturn(0);
+
+    [SysAbiExport(
+        Nid = "wPJGwI2RM2I",
+        ExportName = "sceNgs2VoiceGetStateFlags",
+        Target = Generation.Gen4 | Generation.Gen5,
+        LibraryName = "libSceNgs2")]
+    public static int Ngs2VoiceGetStateFlags(CpuContext ctx) => ctx.SetReturn(0);
+
     [SysAbiExport(
         Nid = "i0VnXM-C9fc",
         ExportName = "sceNgs2SystemRender",
@@ -263,7 +291,6 @@ public static class Ngs2Exports
 
     private static bool TryCreateHandle(CpuContext ctx, uint type, ulong ownerHandle, out ulong handle)
     {
-        handle = 0;
         if (!KernelMemoryCompatExports.TryAllocateHleData(ctx, HandleStorageSize, 16, out handle))
         {
             return false;
@@ -271,11 +298,18 @@ public static class Ngs2Exports
 
         Span<byte> data = stackalloc byte[(int)HandleStorageSize];
         data.Clear();
-        BinaryPrimitives.WriteUInt64LittleEndian(data[0..8], handle);
         BinaryPrimitives.WriteUInt64LittleEndian(data[8..16], ownerHandle);
         BinaryPrimitives.WriteUInt32LittleEndian(data[16..20], 1);
         BinaryPrimitives.WriteUInt32LittleEndian(data[24..28], type);
-        return ctx.Memory.TryWrite(handle, data);
+        if (!ctx.Memory.TryWrite(handle, data))
+        {
+            return false;
+        }
+
+        // Offset 0 doubles as a vtable slot for guest code that treats this handle as a C++
+        // object; stamp it with the shared dummy vtable instead of a self-referential value.
+        KernelMemoryCompatExports.TryWriteDummyVtable(ctx, handle);
+        return true;
     }
 
     private static bool TryClearGuestBuffer(CpuContext ctx, ulong address, ulong length)